std::copysign

From Cppreference

C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Numerics library
Common mathematical functions
Functions Basic operations abs(int) labs llabs abs(float) fabs div ldiv fmod (C++11) remainder (C++11) remquo (C++11) fma (C++11) fmax (C++11) fmin (C++11) fdim (C++11) nan nanf nanl (C++11) (C++11) (C++11) Exponential functions exp exp2 (C++11) expm1 (C++11) log log10 log1p (C++11) ilogb (C++11) logb (C++11) Power functions sqrt cbrt (C++11) hypot (C++11) pow Trigonometric and hyperbolic functions sin cos tan asin acos atan atan2 sinh cosh tanh asinh (C++11) acosh (C++11) atanh (C++11) Error and gamma functions erf (C++11) erfc (C++11) lgamma (C++11) tgamma (C++11) Nearest integer floating point operations ceil floor round lround llround (C++11) (C++11) (C++11) trunc (C++11) nearbyint (C++11) rint lrint llrint (C++11) (C++11) (C++11) Floating point manipulation functions frexp ldexp scalbn scalbln (C++11) (C++11) modf nextafter nexttoward (C++11) (C++11) copysign (C++11) Classification fpclassify (C++11) isfinite (C++11) isinf (C++11) isnan (C++11) isnormal (C++11) signbit (C++11) Macro constants HUGE_VAL HUGE_VALF (C++11) HUGE_VALL (C++11) FP_INFINITE (C++11) FP_NAN (C++11) FP_NORMAL (C++11) FP_SUBNORMAL (C++11) FP_ZERO (C++11)

Defined in header <cmath>
float       copysign( float x, float y );		(C++11 feature)
double      copysign( double x, double y );		(C++11 feature)
long double copysign( long double x, long double y );		(C++11 feature)

Composes a floating point value with the magnitude of x and the sign of y.

[edit] Parameters

x, y

-

floating point values

[edit] Return value

floating point value with the magnitude of x and the sign of y

[edit] See also

abs(float) fabs	absolute value of an absolute value of an floating point value (|x|) (function)
signbit (C++11)	checks if the given number is negative (function)